Electrical insulating potential of aluminum nitride under irradiation with fast electrons

In order to evaluate the electrical insulating potential of aluminium nitride as a radio frequency (rf) heating device, neutral beam injectors, magnetic coils, etc. in fusion reactors environments, the current–voltage (I–V) characteristics and electrical conductivity of poly-crystalline aluminum nitride, doped with 1 wt% Y2O3 (AlN–1 wt% Y2O3) have been measured before and during irradiation with 1 MeV electrons at temperatures up to 723 K. The I–V characteristics of AlN without irradiation are non-linear, while those with irradiation exhibit hysteresis. Blocking effect without irradiation is considered, and it changes with fast electron irradiation. Inconsistency in the I–V characteristics of AlN between positive and negative polarity during irradiation is found, and it is thought to be due to the electron charge deposition onto the single surface of the specimen. No bulk and surface RIED are found up to 1.5×10−5 dpa. If the alpha-particles produced by high neutrons are assumed to be negligible, then AlN can be used as an alternative candidate material for the coating on the blanket of fusion reactors, because of the absence of severe thermally stimulated conductivity (TSC) and bulk and surface degradation under fusion reactors environments.